Why do we 'follow' a clue? Blame a Greek monster.

Every time a detective 'follows a clue,' they are, without knowing it, unspooling a ball of thread through a monster's maze. The word 'clue' is simply a modernized spelling of 'clew' — Old English for a ball of yarn or thread — and it carried that literal meaning for centuries before it ever meant a hint.

The pivot point is the myth of Theseus and the Minotaur. Ariadne gave Theseus a ball of thread — a clew — to trail behind him as he entered the labyrinth at Knossos, so he could find his way back out after killing the beast. That image of thread-as-guide was so vivid and so durable that English speakers began using 'clew' as a metaphor for anything that helps you navigate a mystery.

By the 17th century, the metaphorical sense had taken firm hold. The spelling drifted to 'clue' over the following two centuries, the physical ball of yarn quietly forgotten. What remained was the logic of it: a thread you follow, step by step, until you find your way out.